Project Summary The Transgenic and Chimeric Mouse Facility has been continuously funded by the NCI CCSG since 1989. Drs. Stephen Liebhaber and Nancy Cooke, Professors of Genetics and Medicine, have provided leadership as Co- Directors to this Shared Resource since 1993. Both individuals are experienced investigators with considerable expertise in transgenic and chimeric mouse generation and analysis, and mammalian gene targeting. An experienced technical team led by Dr. Jean Richa provides expertise in a range of transgenic technologies, enabling the facility to regularly introduce new and improved services. Among the services provided by the Transgenic and Chimeric Mouse Facility are: generation of transgenic mice via microinjections of DNA into fertilized oocyte; generation of chimeric mice via injection of embryonic stem cells into blastocysts; direct genome editing (Zn finger, TALEN, and CRISPR/Cas9) by microinjection of RNA and DNA into fertilized embryos; embryo re-derivation; embryo and sperm cryopreservation; in vitro fertilization; centralized and monitored cryopreservation storage; and maintenance of generally useful mouse lines including those for recombination-activation gene expression. The facility uses state-of-the-art laser conditioning of the zona to facilitate IVF and has intracytoplasmic sperm injection capability on-line to complement the in vitro fertilization service. Newly developed services during the current funding period include the major expansion of cryopreservation services with corresponding expansion of the centralized and dedicated cryopreservation facility, integration of mouse ES microinjection service with a centralized gene knock-out core facility, and direct genome editing by Zn-finger, TALEN and CRISPR-Cas9 technologies. In the reporting period (10/01/13- 09/30/14), Cancer Center members accounted for 46% of total Facility users and those with peer-reviewed funding accounted for 42%. This compares favorably with our request for 21% of the total budget from the CCSG. Additional Institutional support is provided in the form of funding for equipment maintenance and facility infrastructure upgrades and maintenance.